huming tone pots

[assiros]

Don't know if anyone can help me with this.

Have shielded my strat, but notice that whenever the middle or neck pickup is selected all is quiet if the tone controls are full on. If I turn them down, I get a progressively louder hum. What's more, if the tone controls are down, then if I touch the strings, the hum gets louder still!

Does not happen with the bridge pickup, I guess coz it does not involve a tone control.

Any ideas as to what the problem is. Not sure if it was like it before as I'd not paid that much attention.

Andy.

[UnklMickey]

hi Andy,

welcome to GuitarNuts2

it sounds to me like your tone pots aren't grounded properly.

my guess is, your string ground is connected to the same place as the ground of your tone pot / tone cap circuit, but that point isn't connected to the low terminal of the volume control, and the sleeve of the output jack.


unk

[assiros]

Thanks for the reply. I just followed the shielding instructions from GuitarNuts.

The strings are grounded via a wire that goes the shielding inside the control cavity. There is no wire going from their to the vol pot......but should a contact be made via the shielding on the back of the scratch plate. Or does this sheilding not contact the low terminal anyway.

If not, how do you suggest I make the necessary contact?

Thanks, Andrew

[UnklMickey]

hi Andrew,

i think i see where you got de-railed.

from QTB:

"18 - Remove any wire which runs from a control (pot or switch) terminal to a control body. In it's place, run a #20 or #22 insulated wire from the control terminal to the ring terminal on the capacitor (i.e. to signal ground)."

this doesn't specifically mention the tone cap, but, it should.

one end of the tone cap is presently connected to the case of the tone pot.

you need to disconnect this end, and connect it to the ring terminal. (signal ground, star ground or whatever you choose to call it.)

that should take care of it.


good luck,

unk

[assiros]

Hi Unk

Thanks. That makes sense and seems pretty straightforward.....except I have to restring my guitar again!

Will report back on my success, or lack thereof!

Thanks again for taking the time to advise me, much appreciated.

Regards, Andy.

[UnklMickey]

you're welcome Andy.